PSI - Issue 71

Shreebanta Kumar Jena et al. / Procedia Structural Integrity 71 (2025) 103–110

110

5. Conclusion The salient outcomes of fatigue test studies on tube specimens having through thickness a single circular hole subjected to remote in-phase and 90 ° out-of-phase axial-torsion conditions for SA 333 Gr. 6 are summarized below. ● The directions of maximum principal strains have been measured using DIC. Measured localized principal strain directions rotate for remote out-of-phase conditions, however, they remain stationary for remote in phase conditions. ● The localized peak equivalent strain changes its position along the hole periphery for remote out-of-phase conditions whereas it remains fixed for remote in-phase conditions. ● For a given tube hole diameter and set of remote axial and torsional strain amplitudes, measured localized equivalent strain amplification is higher for in-phase conditions leading to smaller test fatigue life. References Arora P, Gupta SK, Bhasin V, Singh RK, Sivaprasad S and Tarafder S. 2016, Testing and assessment of fatigue life prediction models for Indian PHWRs piping material under multi-axial load cycling, Int. J. Fatigue, 85, 98-113. Arora P, Samal MK, Gupta SK, and Chattopadhyay J, Assessment of Cyclic Plasticity Behaviour of Primary Piping Material of Indian PHWRs Under Multiaxial Loading Scenario, Lect. Notes Mech. Eng., 2021, 227 – 247. Arora P, Samal MK, Gupta SK, and Chattopadhyay J, 2021, Proposing an improved cyclic plasticity material model for assessment of multiaxial response of low C-Mn steel, Int. J. Fatigue 142, 105888. Arora P, Samal MK, Gupta SK, and Chattopadhyay J, 2019. Development of new critical plane model for assessment of fatigue life under multi axial loading conditions, Int. J. Fatigue, 129, 105209. Arora P, Samal MK, Gupta SK, and Chattopadhyay J,2020. Validating generality of recently developed critical plane model for fatigue life assessments using multiaxial test database on seventeen different materials, Fatigue Fract. Eng. Mater. Struct. 43, 1327 – 1352. Liao D, Zhua S, Correiac JAFO, De Jesusc AMP and Calçadac R. 2018. Computational framework for multiaxial fatigue life prediction of compressor discs considering notch effects, Engineering Fracture Mechanics, 202, 423-435. E2207-15R21 (ASTM), Standard practice for strain-controlled axial torsional fatigue testing with thin-walled tubular specimens. 2015, 03.01. Gates N and Fatemi A,2014. Notched fatigue behavior and stress analysis under multiaxial states of stress, Int. J. Fatigue, 67, 2 – 14. Gates N and Fatemi A, 2016. Notch deformation and stress gradient effects in multiaxial fatigue, Theor. Appl. Fract. Mech. 84, 3 – 25. Gao Z, Qiu B, Wang X and Jiang Y, 2010. An investigation of fatigue of a notched member, Int. J. Fatigue 32, 1960 – 1969. Gupta SK, Fesich TM, Schuler X, Bhasin V, Vaze KK, and Roos E,2011. A critical plane-based model for fatigue assessment under fixed and rotating principal direction loading, Div-II: Paper ID: 624, Transactions, SMiRT 21. Jena SK, Arora P, Gupta SK, and Chattopadhyay J. Validation of notch stress estimation schemes for low C – Mn steel. 2022. Fatigue Fract. Eng. Mater. Struct.;1-20. Jena SK, Arora P, Gupta SK, and Chattopadhyay J,2023. Fatigue experiments and life predictions of notched C -Mn steel tube, Int. J. Fatigue 169,1 15. Jena SK, Arora P, Gupta SK, and Chattopadhyay J, 2024. Axial/torsional fatigue tests on notched tubular specimens of carbon steel and life estimation using theory of critical distance method, Procedia Structural Integrity 60,115-122. Jena SK, Arora P, Gupta SK, and Chattopadhyay J, 2025. Effect of Strain Gradients on Fatigue Life of C-Mn Steel Notched Tubes Under Axial and Torsion Loads: Tests and Analyses, Fatigue Fract. Eng. Mater. Struct. 4,1589-1611. Jena SK, Arora P, Gupta SK, and Chattopadhyay J, 2025. Measuring Localized Strains and Capturing Fatigue Crack Initiation Event Using Digital Image Correlation Technique, Springer, 3,659-670. Lamba HS, Sidebottom OM. Cyclic plasticity for nonproportional paths: part 1 cyclic hardening, erasure of memory, and subsequent strain hardening experiments: part 2 – comparison with prediction of three incremental plasticity models. ASME J Eng Mater Technology 1978; 100:96 – 103. Kanazawa K, Miller KJ, Brown MW.1979. Cyclic deformation of 1% Cr – Mo – V steel under out-of-phase loads. Fatigue Eng Mater Struct 2:217 – 28. Gladskyi M and Fatemi A,2013. Notched fatigue behavior including load sequence effects under axial and torsional loadings, Int. J. Fatigue 55, 43 – 53. Sakane M, Zhang S, and Kim T,2011. Notch effect on multiaxial low cycle fatigue, Int. J. Fatigue 33, 959 – 968. Sadd MH. Elasticity: Theory, Applications, and Numerics, Third Edition,2014, ISBN:978-0-12-408136-9. Taira S, Inoue T, Yoshida S. 1968. Low cycle fatigue under multiaxial stress in the case of combined cyclic tension compression and cyclic torsion out-of-phase at elevated temperature. In: Proceedings of 11 th Japan congress on materials research, vol. 5;. 60 – 65. Vibhanshu P, Arora P , Gupta SK , Khutia N , Dey PP.2023. An improved strain path dependent model under multiaxial cyclic loading for simulating material response of low C-Mn steel, Int. J. Fatigue 167 A, 107322.